Segmented Roller Clutch for Smooth Torque Transmission Switching

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Solution Overview

Problem

Existing driving force transmission apparatuses face challenges in smoothly switching between on and off states, as rollers may fail to disengage properly, leading to incomplete disengagement and inefficient state transitions.

Innovation Solution

A driving force transmission apparatus with an outer and inner peripheral portion, a space containing alternating large and small sub-spaces, rolling elements, an elastic body, and a switching member that displaces axially to control the engagement and disengagement of rolling elements, ensuring seamless transitions between on and off states by utilizing a two-way clutch and electromagnetic clutch for precise control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If rollers are pressed by elastic members to engage with both inner ring and outer ring, then torque transmission is achieved, but smooth disengagement becomes difficult

Engineering Contradiction:
Improvetorque transmissionVSAvoiddisengagement smoothness
Core Design Contradiction:
PowerVSEase of operation

Solution Approach 1:

The space between inner and outer rings is segmented into multiple sub-spaces (first sub-space, second sub-space, third sub-space) with different circumferential widths. Rollers can be positioned in different sub-spaces to achieve different functional states: engaged state (both rollers in narrow second sub-space), disengaged state (both rollers in wide first or third sub-space), and one-way clutch state (one roller in narrow second sub-space, one roller in wide first or third sub-space). This segmentation allows smooth transition between states by providing intermediate positions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically transitions between different engagement states by controlling the radial positions of rollers relative to the inner and outer rings. The controlling cage and rotational cage rotate relative to each other, causing rollers to move radially inward or outward. This dynamic positioning allows the system to switch between engaged, disengaged, and one-way clutch states, enabling smooth state transitions while maintaining torque transmission capability when needed.

Inventive Principle:
Principle #15Dynamics

2Power

If both rollers of each pair are in engagement with inner ring and outer ring, then torque transmission is maximized, but state switching reliability decreases

Engineering Contradiction:
Improvetorque transmissionVSAvoidstate switching reliability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

Different sub-spaces have different circumferential widths, creating local quality variations in the engagement geometry. The narrow second sub-space provides strong engagement for torque transmission, while the wide first and third sub-spaces facilitate easy disengagement. By positioning rollers in different sub-spaces, the system achieves reliable state switching with distinct positional differences between engaged and disengaged states, reducing the risk of incomplete transitions.

Inventive Principle:
Principle #3Local quality

3Reliability

If magnetic force is increased to ensure reliable engagement, then torque transmission reliability improves, but device size and complexity increase

Engineering Contradiction:
Improveengagement reliabilityVSAvoidelectromagnetic clutch size
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces part of the electromagnetic clutch mechanism with a mechanical two-way clutch system using rollers, elastic members, and geometrically defined sub-spaces. The two-way clutch provides reliable engagement through mechanical interference fit in the narrow second sub-space, reducing dependence on high magnetic force. This substitution allows for a more compact electromagnetic clutch design while maintaining reliable engagement through the mechanical advantage of the segmented space geometry.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables smooth switching between rotational force transmission and non-transmission states, ensuring reliable operation and efficient state changes, reducing magnetic force requirements and allowing for a compact electromagnetic clutch design.

Implementation Method 1

an elastic body to elastically urge the rolling elements of the at least one pair away from each other in the circumferential direction

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

allowing for a compact electromagnetic clutch design

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Data Source

PatentEP3163108B1Driving force transmission apparatus
Publication Date: 2020.05.13 JTEKT CORP
  • EP3163108B1 patent drawingFigure 1
  • EP3163108B1 patent drawingFigure 2
  • EP3163108B1 patent drawingFigure 3

AI summary

Displacement of a switching member in a first direction causes rolling elements of each pair to come out of engagement with an outer peripheral portion or an inner peripheral portion and form clearances therewith, resulting in an OFF state of a driving force transmission apparatus. Displacement of the switching member in a second direction causes a downstream one of the rolling elements of each pair in the direction of rotation to come into zero clearance engagement with the outer peripheral portion and the inner peripheral portion, with a clearance formed between an upstream one of the rolling elements of each pair and the outer peripheral portion or the inner peripheral portion, resulting in an ON state of the driving force transmission apparatus.